(lambda (formats)
  (var new-formats
    (.map (Object.keys formats) (lambda (extension)
      (var target (.-target (get formats extension)))
      (var is-default (=== "null" (String extension)))
      (return (+ (?: is-default "null" (JSON.stringify extension))
        ": require('glagol/formats/" target ".js')")))))
  (return (+ "{ " (new-formats.join ", ") "} ")))
